Discontinuous reception (DRX) is a known technique in telecommunications, which is used to reduce the power consumption of user terminals. Discontinuous reception may be used in different situations, such as for instance in a radio resource control (RRC) idle state or in a RRC connected state. During discontinuous reception in RRC connected state, a user terminal stops monitoring one or more signalling channels (layers 1 and 2) but a RRC connection (layer 3) is generally still maintained for the user terminal during that time.
FIG. 1 schematically illustrates an exemplary DRX cycle as disclosed in “3GPP TS 36.321 V10.4.0 (2011-12), Technical Specification, 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control (MAC) protocol specification (Release 10)”, page 7. When the DRX functionality is configured, a user equipment (UE) is allowed to monitor a downlink control channel discontinuously, such as for example a physical downlink control channel (PDCCH) as defined in “3GPP TS 36.211 V10.4.0 (2011-12), Technical Specification, 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 10)”.
In particular, “3GPP TS 36.300 V10.6.0 (2011-12), Technical Specification, 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 10)” discloses, in its section 12 entitled “DRX in RRC_CONNECTED”, characteristics of a known, exemplary DRX functionality.
It is desirable to improve existing telecommunication systems with discontinuous reception without increasing, or at least without excessively increasing, the implementation and architecture complexity and the associated equipment costs.